vfio: return mr from vfio_get_xlat_addr

Modify memory_get_xlat_addr and vfio_get_xlat_addr to return the memory
region that the translated address is found in.  This will be needed by
CPR in a subsequent patch to map blocks using IOMMU_IOAS_MAP_FILE.

Also return the xlat offset, so we can simplify the interface by removing
the out parameters that can be trivially derived from mr and xlat.

Lastly, rename the functions to  to memory_translate_iotlb() and
vfio_translate_iotlb().

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: John Levon <john.levon@nutanix.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Link: https://lore.kernel.org/qemu-devel/1747661203-136490-1-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 7 insertions, 25 deletions

diff --git a/system/memory.c b/system/memory.c
index 63b983efcd..306e9ff9eb 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -2174,18 +2174,14 @@ void ram_discard_manager_unregister_listener(RamDiscardManager *rdm,
 }
 
 /* Called with rcu_read_lock held.  */
-bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
-                          ram_addr_t *ram_addr, bool *read_only,
-                          bool *mr_has_discard_manager, Error **errp)
+MemoryRegion *memory_translate_iotlb(IOMMUTLBEntry *iotlb, hwaddr *xlat_p,
+                                     Error **errp)
 {
     MemoryRegion *mr;
     hwaddr xlat;
     hwaddr len = iotlb->addr_mask + 1;
     bool writable = iotlb->perm & IOMMU_WO;
 
-    if (mr_has_discard_manager) {
-        *mr_has_discard_manager = false;
-    }
     /*
      * The IOMMU TLB entry we have just covers translation through
      * this IOMMU to its immediate target.  We need to translate
@@ -2195,7 +2191,7 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
                                  &xlat, &len, writable, MEMTXATTRS_UNSPECIFIED);
     if (!memory_region_is_ram(mr)) {
         error_setg(errp, "iommu map to non memory area %" HWADDR_PRIx "", xlat);
-        return false;
+        return NULL;
     } else if (memory_region_has_ram_discard_manager(mr)) {
         RamDiscardManager *rdm = memory_region_get_ram_discard_manager(mr);
         MemoryRegionSection tmp = {
@@ -2203,9 +2199,6 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
             .offset_within_region = xlat,
             .size = int128_make64(len),
         };
-        if (mr_has_discard_manager) {
-            *mr_has_discard_manager = true;
-        }
         /*
          * Malicious VMs can map memory into the IOMMU, which is expected
          * to remain discarded. vfio will pin all pages, populating memory.
@@ -2216,7 +2209,7 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
             error_setg(errp, "iommu map to discarded memory (e.g., unplugged"
                          " via virtio-mem): %" HWADDR_PRIx "",
                          iotlb->translated_addr);
-            return false;
+            return NULL;
         }
     }
 
@@ -2226,22 +2219,11 @@ bool memory_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
      */
     if (len & iotlb->addr_mask) {
         error_setg(errp, "iommu has granularity incompatible with target AS");
-        return false;
-    }
-
-    if (vaddr) {
-        *vaddr = memory_region_get_ram_ptr(mr) + xlat;
-    }
-
-    if (ram_addr) {
-        *ram_addr = memory_region_get_ram_addr(mr) + xlat;
-    }
-
-    if (read_only) {
-        *read_only = !writable || mr->readonly;
+        return NULL;
     }
 
-    return true;
+    *xlat_p = xlat;
+    return mr;
 }
 
 void memory_region_set_log(MemoryRegion *mr, bool log, unsigned client)